Cape Town: KPMG's new chief executive in South Africa said on Thursday she would make sweeping changes to ensure the firm did not repeat "greatly disappointing" work it did for business friends of President Jacob Zuma.

Nhlamu Dlomu, who took up the top job in South Africa after most of the local board was sacked last month, said an announcement would be made in the coming days about an independent inquiry into its work at firms owned by the Guptas - three Indian-born businessmen with close ties to Zuma.

"I have personally been greatly disappointed by how far we have fallen short of the standards we set ourselves," Dlomu told parliament's committee of public accounts.

"I am determined that these mistakes do not happen again, which is why we have already made a number of changes. I am leading other reforms."

Dlomu said any person found by the investigation to have failed to do their job would be held accountable. She said the changes would also strengthen governance and ensure decision-making was more centralized.

KPMG has been dropped by at least three companies listed in Johannesburg. Big banks such as Barclays Africa and Standard Bank are also considering whether they should drop the firm.

KPMG is under investigation by South Africa's Independent Regulatory Board for Auditors. Dlomu said it was cooperating with the probe and has handed over requested documents.

Several other global firms have faced problems due to their work for the Gupta brothers including business consultancy McKinsey and public relations agency Bell Pottinger.